This invention relates in general to a technique for diagnosing Attention Deficit Hyperactivity Disorder (ADHD) and more particularly to a technique for measuring and objectively analyzing an individual""s peripheral temperature variability to determine values indicative of ADHD.
ADHD is the most common neurobehavioral disorder of childhood as well as among the most prevalent health conditions affecting school-aged children. Between 4% and 12% of school age children (several millions) are affected. $3 billion is spent annually on behalf of students with ADHD. Moreover, in the general population, 9.2% of males and 2.9% of females are found to have behavior consistent with ADHD. Upwards of 10 million adults may be affected.
ADHD is a difficult disorder to diagnose. The core symptoms of ADHD in children include inattention, hyperactivity, and impulsivity. ADHD children may experience significant functional problems, such as school difficulties, academic underachievement, poor relationships with family and peers, and low self-esteem. Adults with ADHD often have a history of losing jobs, impulsive actions, substance abuse, and broken marriages. ADHD often goes undiagnosed if not caught at an early age and affects many adults who may not be aware of the condition. ADHD has many look-alike causes (family situations, motivations) and co-morbid conditions (depression, anxiety, and learning disabilities) are common.
Diagnosis of ADHD currently involves a process of elimination using written and verbal assessment instruments. However, there is no one objective, independently validated test for ADHD. Various objective techniques have been proposed but have not yet attained widespread acceptance. These include:
1. The eye problem called convergence insufficiency was found to be three times more common in children with ADHD than in other children by University of California, San Diego researchers.
2. Infrared tracking to measure difficult-to-detect movements of children during attention tests combined with functional MRI imaging of the brain were used by psychiatrists at McLean Hospital in Belmont, Mass. to diagnose ADHD in a small group of children (Nature Medicine, Vol. 6, No. 4, April 2000, Pages 470-473).
3. Techniques based on EEG biofeedback for the diagnoses and treatment of ADHD are described by Lubar (Biofeedback and Self-Regulation, Vol. 16, No. 3, 1991, Pages 201-225).
4. U.S. Pat. No. 6,097,980, issued Aug. 1, 2000, inventor Monastra et al, discloses a quantitative electroencephalographic process assessing ADHD.
5. U.S. Pat. No. 5,913,310, issued Jun. 22, 1999, inventor Brown, discloses a video game for the diagnosis and treatment of ADHD.
6. U.S. Pat. No. 5,918,603, issued Jul. 6, 1999, inventor Brown, discloses a video game for the diagnosis and treatment of ADHD.
7. U.S. Pat. No. 5,940,801, issued Aug. 17, 1999, inventor Brown, discloses a microprocessor such as a video game for the diagnosis and treatment of ADHD.
8. U.S. Pat. No. 5,377,100, issued Dec. 27, 1994, inventors Pope et al., discloses a method of using a video game coupled with brain wave detection to treat patients with ADHD.
9. Dr. Albert Rizzo of the Integrated Media Systems Center of the University of Southern California has used Virtual Reality techniques for the detection and treatment of ADHD.
10. U.S. Pat. No. 6,053,739, inventors Stewart et al., discloses a method of using a visual display, colored visual word targets and colored visual response targets to administer an attention performance test.
For Further Reference:
U.S. Pat. No. 5,377,100, issued Dec. 27, 1994, inventors Patton et al., discloses a system for managing the psychological state of an individual using images.
U.S. Pat. No. 6,117,075 inventor Barnea discloses a method of measuring the depth of anesthesia by detecting the suppression of peripheral temperature variability.
There are several clinical biofeedback and physiologic monitoring systems (e.g. Multi Trace, Bio Integrator). These systems are used by professional clinicians. Although skin temperature spectral characteristics have been shown to indicate stress-related changes of peripheral vasomotor activity in normal subjects, there has been no disclosure of use of variations in skin-temperature response to assist in diagnosing ADHD. (See: Biofeedback and Self-Regulation, Vol. 20, No. 4, 1995).
As stated above, the primary method for diagnosing ADHD is the use of a bank of written and verbal assessment instruments. These are designed to assess the individual for behavioral indicators of criteria established by American Medical Association (AMA) as described in the Diagnostic and Statistics manual (DSM-W). Psychiatrists, psychologists, the school psychologist or other licensed practitioner administer these assessment instruments. In some cases those individuals who meet DSM-IV criteria for ADHD diagnosis are prescribed a drug such as Ritalin. Behavioral observations of the patient while on Ritalin are conducted to assess the impact of prescribed medication.
There is thus a need for a simple, inexpensive, reliable, and objective technique for the diagnosis of ADHD.
According to the present invention, there is provided a solution to the problems and fulfillment of the needs discussed above.
According to a feature of the present invention, there is provided a method for determining two threshold values, which are subsequently used to determine whether an individual has Attention Deficit Hyperactivity Disorder (ADHD) comprising: providing a group of subjects, a segment of which is known to have ADHD and a segment of which is known to be normal and not have ADHD; testing the group by: (a) sampling the peripheral skin temperatures of left and right like extremities of each of said subjects, during a predetermined time interval when said subjects are in a sensory deprived state to provide respective left and right sampled peripheral skin temperature data; (b) a first processing of at least one of said left and right sampled peripheral skin temperature data with a Fast Fourier Transform (FFT) to derive a first spectral signature having magnitude values; (c) a second processing of both left and right sampled peripheral skin temperature data to derive temporally correlated differential data; (d) the second processing further filtering said differential data with a high pass filter to produce filtered data with near d.c. components removed; (e) the second processing finally applying an FFT to said filtered differential data to derive a second spectral signature having magnitude values; and (f) final processing of the first and second spectral signatures for all of the subjects of the group to determine two threshold values which are complimentarily effective for determining whether or not an individual has ADHD when tested by said testing procedure.
The invention has the following advantages.
1. A technique for objectively diagnosing ADHD is provided which is simple, inexpensive, and reliable.